Sunday, April 07, 2013
"A grove of graceful cherry trees has been planted as a tribute to graduates of Japanese ancestry, in honor of their contributions to society and in recognition of the educational excellence of the University of California." Quoted from: Cherry Tree Project Plaque
Posted by ken osborn at 12:26 PM
Friday, January 18, 2013
Creating a Flickr Slide Show
(c) Ken Osborn 2013
You can make a slide show based on tags, like this one from my sets tagged 'Dickens.'
|Entering Information to Access Flickr Images|
To find your id number use idGettr at http://idgettr.com/.
|idGettr will Get Your Unique Flickr ID Number|
After you get your ID you then enter either a set URL with or without tags or just tags. If you enter just tags it will grab everything in your Flickr stream with the tag so don't get too crazy because if you are like me you may have a lot of images under some particular tag.
|HTML Code for Website|
Sunday, January 13, 2013
Do You Really Need a Zoom Lens
Ken Osborn (c) 2013
If you have a camera that can take a 25 MP (mega-pixel) image, you may have asked yourself "why do I need a zoom lens?" If, like me, you aren't printing posters and mainly show your photos on your website, why not just use a good prime 50 mm lens? Maybe a 70 mm if you are doing portraiture. With a zoom you can compose the way you want in the field, but if you are going to resize the image prior to posting, what is the difference between doing that and cropping from a larger image? After all, you have all those extra pixels does it really matter how you waste them: by reducing resolution or by cropping them away?
I decided the only way to answer that question was to try it.
I used an 18-55 mm zoom lens on a Pentax K5IIS to take two photos. The first at a zoom of 18 mm and the second at 55 mm.
|Image 1: 18 mm zoom|
|Image 2: 55 mm zoom|
The 18 mm image was cropped to the focusing chart for an image size of 423 pixels wide. The 55 mm image was cropped to the focusing chart and then resized to 423 pixels wide. So now both images have the same target filling the view and are both at the same final resolution. The results are immediately below with the 55 mm zoom photo on the left and the 18 mm photo on the right. (Click on the image for a larger view.)
|Comparing Resizing (left) vs Cropping (right)|
I have concluded I will keep my telephoto!
Saturday, January 05, 2013
Restoring Old Comics and Memories
Ken Osborn © 2012
If you know Photoshop, like old comics, and would like to see what they looked like new, read on.
I was and still am a big fan of Carl Barks duck stories: Donald Duck; his nephews Huey, Dewey, and Louie; Uncle Scrooge and a host of relatives. Trying to refresh my memory on a Scrooge adventure I found an incredible resource, the Duck Comics Revue by Geoff Moses at http://duckcomicsrevue.blogspot.com/.
Geoff’s blog is filled with all sorts of goodies including panels from some well remembered stories. But after a few decades the print had faded. Those old dime comics were printed on a cheaper paper and were not intended to last forever.
But with Photoshop it’s possible to restore these faded memories to their former glory. Below are an original scan of a comic panel from the Duck Comics Revue followed by the restored version.
|Restored Contrast and Colors|
Starting with the scan, open it in Photoshop and take a look at the histogram.
|Histogram Using Photoshop Levels|
The histogram is not evenly spread across the full width with a space at the right (highlights) end consistent with the yellow faded appearance. Mouse click the ‘Auto’ button to improve the contrast.
|Auto Adjust Levels|
|Eye Dropper for Bright Whites|
|Maybe too white|
This is probably a bit harsh and the original was probably somewhere between bright white and faded yellow, so fade the levels about 50%.
|Levels Faded 50%|
Scanning the comic book will usually leave the print just a little soft, so a bit of sharpening may make the content a little more readable but it’s easy to overdo it so you may need to fade the sharpening.
Sharpening a Little Harsh with Halos
Before leaving the topic, here is one more example from a classic Donald Duck adventure, Trick or Treat (1952).
|Original from Trick or Treat|
And that’s it. If you want to see a restored version of a 1950’s 3D Donald Duck giveaway, check it out at http://duckcomicsrevue.blogspot.com/2013/01/witch-hazel-remastered.html on Geoff Moses’ blog.
Friday, December 21, 2012
A guest presentation by Linnea Hoover, Laboratory Supervisor 2012
Ever wonder how the quality of your drinking water is ensured? A combination of good water sources, regulations that set the standards, water treatment infrastructure, and a testing laboratory. But it takes people to operate the infrastructure and chemists, microbiologists, and technicians to test the water quality. Who are these people?
Linnea Hoover, A former colleague who supervises a chemistry section at the East Bay Municipal Utility District's Laboratory, has combined her interests in science, photography, and art to show the human side of the laboratory. In a gallery of photographs that display the many faceted personalities in the laboratory, Linnea has matched her staff with icons of art and history in a creative collection you can view at:
While the photographic display shows that humor and science can coexist, it is important to remember that the people you saw in the gallery take their jobs seriously and understand the need to maintain and calibrate their instrumentation; perform tests to ensure the results are reproducible and correct; and that when the numbers say a substance is not analytically present its analytical absence is confirmed. When coworkers understand their profession, work as a team, and can even express joy in their work the product will show it.
Wednesday, December 12, 2012
(c) Ken Osborn 2012
I recently joined a photography Meetup that convenes every two weeks to critique a photography challenge (http://www.meetup.com/Tinkering-Toms-and-Tammys-Photography-Group/). The challenge for our second meetup was to capture a progression or stages of time, like the metamorphosis of a butterfly, frying an egg, or changes of the seasons.
I decided to assemble a progression in time with two photos I already had and were separated by several decades. In fact I was not the photographer. A few years ago I assembled a rather large collection of family photographs dating to 1889. Some were still in excellent condition, but many showed the toll of time. Months of work were required to restore many badly faded, mildewed, and otherwise noticeably aged prints. There were two photographs that stood out: a great aunt-in-law, Anna Elizabeth Bell Graham, as a young woman and again in her late years showing a remarkable conformity. While she had obviously aged, the shape and structure of her face was relatively unchanged and her presentation to the camera was the same in both photographs.
I had some prior experience merging photographs of relatives to show the similarities and differences to others in the family, but had not previously seen such a judicious combination. So I decided these photographs of Anna Bell would be assembled into a progression of time for the Meetup photography challenge.
Anna Bell was born Jan 30, 1884 Anna Elizabeth Bell in West Shokan, NY. The photograph below shows her at the age of five with her younger brother Charles. Fortunately it was the practice of past generations to write information, in pencil, on the back of family photos. That practice is seldom practiced today.
When Anna's family moved to Illinois, she grew up in a rural setting surrounded by farmland.
A photograph of Anna as a young woman in her late teens.
A photograph of Anna in her late years.
Using these two photographs and Photoshop, I created a sequence of five images showing how she might have looked over the intervening years.
|Mouse Click for Larger View|
I did not know Anna Bell, but I leave one other photograph that has no information on the back and none of my in-laws know exactly when the photograph was made, but it is visibly neither when she was in her youth nor old age. You can judge for yourself whether the sequence above has recaptured Anna Bell in the intervening years.
Friday, November 30, 2012
Histogram Basics for Photographers
© Ken Osborn 2012
Light meter? Isn’t that something like a sliderule? A few photographers still use light meters but most of us depend on the histogram to tell us if an image is over or under exposed. And some know about histograms but don’t use them because they rely on the camera to make all of the photographic decisions. Nothing wrong with that if you have no desire or need for creative control, but if you’d like to go the next step and not let the camera make all the decisions, then this little tutorial is for you.
A histogram plots light received by the camera’s sensor with light value the horizontal axis and number of pixels on the vertical axis as in the plot below.
Light values for 8 bit pixels range from 0 (no light) to 255 (blown out highlight). The next chart shows light value assignments and the relationship to the Adams Zone System numbers. This makes for a total of 256X256X256 color shades when the Red, Green, and Blue (RGB) channels are combined for full color. Our eyes can see more shades of color than that but it’s close enough and many color printers can’t do any better.
So how do you use a histogram for proper exposure?
Below is a properly exposed photo shot at sunset. There are no blown out highlights or blocked up shadows.
Abandoned Building at Sunset
Now compare to the badly overexposed image below.
Here is the same photo with the histogram superimposed.
Note that the histogram is pushed to the right with no space on the right side: the highlights are blown.
An underexposed version of the same scene.
Perhaps you want that nighttime look. That’s good and exactly why you want control over your shot. Before you look at the histogram below, what will the curve look like?
Of course you knew the curve would be pushed to the left with the shadows blocked, yes?
So what does a ‘proper’ histogram look like? If you don’t want blocked shadows or blown highlights, then you will want a histogram that has nothing extending to the edges, as in the next image.
So that’s it. Properly exposed, a photograph should have neither blocked shadows nor blown highlights. Shadow areas that are too dark have no detail and generally lack interest. Highlights that are blown also have no detail and are usually distracting to the central features of the image.
And now you know what happens to the histogram if the shadows are too dark or the highlights are too bright. Of course that is not to say that the artist’s intention was not have shadows without detail or highlights that dazzled the eyes. After all, photography is an art.